A polyimide resin used as an insulation layer material for a light emitting diode can have excellent heat resistance, stability in a process conducted at a temperature of greater than or equal to about 200° C., and mechanical strength, a low dielectric constant (low-k), and excellent planarization characteristics on a coating surface. Further, a polyimide resin used as an insulation layer material can include a small amount of impurities, which can deteriorate the reliability of a device, and can easily provide a fine pattern. Thus, a polyimide resin as an insulation layer material has drawn lots of attention.
A conventional polyimide resin for forming an insulation layer or a semiconductor protective layer for an organic light emitting diode requires an additional photoresist process and subsequently an etching process using an organic solvent after the patterning. Thus, the manufacturing process can be complex and require additional costs. Further, the device can exhibit resist pattern swelling as well as cause an environmental problem due to the use of an organic solvent.
On the other hand, an organic material remaining in an exposed part may be removed in a dry etching method during formation of a semiconductor circuit protective layer or a pixel crystal layer for an organic light emitting diode
(OLED) display. As used herein, the dry etching selectively removes a residue in an exposed pattern part. Accordingly, there has been research directed to a resin material which is less influenced by the etching in a non-exposed part.
In addition, the resin material needs to include more carbon in order to provide excellent etching resistance. However, there can be a problem because the resin material can be exposed at a high temperature of greater than or equal to about 400° C.